Toothbrush having a uniform, smooth and continuous wall of bristles

ABSTRACT

A toothbrush, either manual or powered, including an elongated member with a head at one end and a handle at the other end. The toothbrush is generally aligned along a central longitudinal axis. The head having a brush face including a brush cavity from which a plurality of bristles extend. The bristles being arranged in a plurality of bristle tufts so as to extend generally perpendicular to the central longitudinal axis. The toothbrush also includes a plurality of lateral support members extending upwardly from a base of the brush cavity. The bristles are attached to the toothbrush by an attachment device provided in the brush cavity. The attachment device engages at least one of the tufts and secures the tuft between adjacent lateral support members. The attachment device includes a bottom edge and a top edge. Each of the lateral support members extend to a predetermined height from the base of the brush cavity so as to reach at least the height of the bottom edge of said attachment device in the brush cavity.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a toothbrush with bristles attached in such amanner to create a uniform, smooth and continuous wall thereof, and moreparticularly, to a toothbrush with means for supporting the toothbrushbristles to achieve a uniform, smooth and continuous wall of bristlesusing conventional staple bristle attachment methods.

2. Discussion of Related Art

Truly continuous smooth bristle bars are not new in the art (see, forexample, U.S. Pat. No. 6,276,021), but have only been achieved using newstaple-less manufacturing technologies. These new manufacturingtechniques, such as IMT, Fusion and AFT, are somewhat complex resultingin high capital cost and long lead times. It has therefore been founddesirable to create continuous smooth bristle bars by utilizingconventional staple technology due to its lower overall cost.

Attempts have been made in the past with limited success to achievesmooth bristle bars utilizing conventional staple technology. Forinstance, simulated bristle bars have been achieved in the past usingindividual square tuft holders placed very close to one another, tominimize the space between tufts. Examples of this manufacturingtechnique are described in U.S. Pat. No. 5,446,940, owned by the sameassignee as this application. A similar technique is described in U.S.Patent Publication No. 2001/0023516, with a “transverse wall” locatedbetween each tuft.

A disadvantage of the above-noted prior art of U.S. Pat. No. 5,446,940is the small “bridge” of plastic required between each tuft. This“bridge” runs flush with the top surface of the brush face, and causes asmall gap A (see FIG. 1) in the bristles as they exit the tuft holes. Asa result, the bristles cannot form a uniform, continuous and smoothwall, as the bristles “merge” from the tuft hole. It has therefore beenfound desirable to create a uniform bristle bar for bristles in atoothbrush with no gaps as the bristles leave the brush face.

The “transverse wall” of the manufacturing technique in U.S. PatentPublication No. 2001/0023516 is needed to maintain the bristles in anear upright position, so that subsequent tufts can be inserted withoutobstructing their access to their respective tuft hole. As is shown inFIG. 2, if the transverse walls are simply removed and the bristlesstapled into the resulting cavity, the bristles tufted into the blankcavity will disadvantageously tend to fall sideways into the cavity, dueto a lack of lateral support. Further problems occur when insertingsubsequent tufts, due to the non-vertical tufts blocking the tuft“holes”. Moreover, by use of this transverse wall, the aforementionedgap results so as to prevent a uniform, continuous and smooth wall ofbristles.

U.S. Patent Publication No. 2001/023516 further describes a method ofusing extra parts in the brush construction to create the “transversewalls”, suggesting the use of metal staples or metal bars. It hastherefore been found desirable to provide a toothbrush which utilizes asingle molded part for the construction of the tuft slot hole. Such aconstruction results in a stronger assembly, which is faster and lesscostly to produce.

Based upon the foregoing, it has been found desirable to provide atoothbrush having a uniform, smooth and continuous wall of bristles,which uses traditional low cost staple techniques and ensures that onceinserted, the bristles remain in a substantially upright verticalorientation with respect to the longitudinal axis of the toothbrush toenable timely insertion of further bristles.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide atoothbrush which overcomes the disadvantages of the aforementioned priorart.

It is also an object of the present invention to provide a toothbrushwhich is manufactured so as to achieve a uniform, smooth and continuouswall of bristles using traditional staple technology.

It is another object of the present invention to provide a method formaking a toothbrush with a uniform, smooth and continuous wall ofbristles which has lower production costs.

It is yet another object of this invention to provide a toothbrush whichhas adequate lateral support for the bristles tufted into the bristlecavity.

It is a further object of the present invention to provide a toothbrushhaving a uniform, smooth and continuous wall of bristles, usestraditional low cost staple techniques, and ensures that once inserted,the bristles remain substantially vertical with respect to thetoothbrush to enable insertion of further bristles.

It is an additional object of this invention to create a uniform bristlebar for bristles in a toothbrush which minimizes gaps as the bristlesleave the brush face.

It is yet another object of this invention to provide a toothbrush whichutilizes a single molded part for the construction of the tuft slothole.

Various other objects, advantages and features of the present inventionwill become readily apparent from the ensuing detailed description andthe novel features will be particularly pointed out in the appendedclaims.

SUMMARY OF THE INVENTION

In accordance with the present invention, a toothbrush having a uniform,smooth and continuous wall of bristles is provided. The toothbrush ofthe present invention has a handle portion at one end thereof and a headportion at the other end thereof. The head portion includes a brush faceand a brush cavity with a plurality of lateral support members extendingupwardly from the brush cavity so as to provide lateral support for theplurality of upwardly extending bristles arranged in a plurality oftufts. In applicant's toothbrush, at least one staple engages at leastone of the plurality of tufts and affixes the at least one of theplurality of tufts between at least two of the lateral support members.In order to prevent gaps between the bristles as they exit the bristlecavity, a leg of the lateral support member extends from a base of thecavity in the direction of the brush face to at least a bottom edge ofthe staple. This arrangement of the tufts in the lateral support memberengaged by a staple enables the bristle of the tufts to engage oneanother at a point in the cavity below the brush face. As a result, theplurality of tufts so joined form a substantially uniform continuouslayer of bristles extending from the brush face.

In accordance with another embodiment of the present invention, atoothbrush is provided having an elongated member having a head at oneend and a handle at the other end, generally aligned along a centrallongitudinal axis, said head having a brush face including a cavity fromwhich a plurality of bristles extend, said plurality of bristles beingarranged in a plurality of tufts so as to extend generally perpendicularto the central longitudinal axis;

-   a plurality of lateral support members extending upwardly from a    base of the brush cavity; attachment means provided in said brush    cavity for engaging at least one of the plurality of tufts and for    securing said one tuft between adjacent lateral support members, the    attachment means having a bottom edge and a top edge; and wherein    each of said lateral support members extends from the base of the    cavity so as to reach a predetermined height in the cavity which is    between the height of the bottom edge of the attachment means and    the brush face.

In accordance with a further embodiment of the present invention, apowered toothbrush is provided having an elongated member having a headat one end and a handle at the other end, generally aligned along acentral longitudinal axis, said head having a brush face including acavity from which a plurality of bristles extend, said plurality ofbristles being arranged in a plurality of tufts so as to extendgenerally perpendicular to the central longitudinal axis; a plurality oflateral support members extending upwardly from a base of the brushcavity; attachment means provided in said cavity at least for engagingone of the plurality of tufts and for securing said one tuft betweenadjacent lateral support members, said attachment means having a bottomedge and a top edge, and wherein each of the lateral support membersextends to a predetermined height from the base of the brush cavity soas to reach at least the height of the bottom edge of said attachmentmeans in said brush cavity.

In accordance with still another embodiment of the present invention, alateral support member for holding bristles in a toothbrush is providedhaving a substantially U-shaped formation formed in a cavity of thetoothbrush, at least one leg of the U-shaped formation extending to apoint between a bottom edge of a staple securing the bristles to thetoothbrush and the brush face.

The tuft in accordance with the present invention may be engaged byarranging the staple between a single lateral support member and a sideedge of the cavity. Moreover, the lateral support members may extend toa point between the brush face and the bottom edge of the staple.

Given the outward forces created by the presence of a staple, it ispreferred to have the height of the lateral support wall rise above thebottom of the staple. However, to ensure that the bristles betweenadjacent tufts are in full contact (with no gaps) prior to leaving thetuft hole, the lateral support wall should stop short of the top surfaceof the brush face. The final convergence point of these bristles iscontrolled by the top-most width of the lateral support wall, thedistance between the top of the wall and the brush face, and angle ofthe sides of the wall.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description, given by way of example, but notintended to limit the invention solely to the specific embodimentsdescribed, may best be understood in conjunction with the accompanyingdrawings in which:

FIG. 1 is a cross-sectional view of a prior art method for attachingbristles in a bristle cavity as taught in U.S. Patent Appln. PublicationNo. 2001/0123516.

FIG. 2 is a cross-sectional view of a prior art method for attachingbristles in a bristle cavity without any support members.

FIG. 3 is a front perspective view of a preferred embodiment of atoothbrush in accordance with the teachings of the present invention.

FIG. 4 is an enlarged top view of the head portion of the toothbrushshown in FIG. 3 with the bristles removed.

FIG. 5 is a cross-sectional view of a first preferred embodiment of anassembly and process for providing a uniform, smooth and continuous wallof bristles in the brush cavity of the toothbrush of FIG. 3.

FIG. 6 is a cross-sectional view of another preferred embodiment of anassembly and process in accordance with the teachings of this inventionfor providing a uniform, smooth and continuous wall of bristles in thebrush cavity of the toothbrush of FIG. 3.

FIG. 7 is cross-sectional view a of another preferred embodiment of anassembly and process in accordance with the teachings of this inventionfor providing a uniform, smooth and continuous wall of bristles in thebrush cavity of the toothbrush of FIG. 3.

FIG. 8 is a cross-sectional view of another preferred embodiment of theassembly and process in accordance with the teachings of this inventionfor providing a uniform, smooth and continuous wall of bristles in thebrush cavity of the toothbrush of FIG. 3.

FIG. 9 is a top view of another preferred embodiment an assembly andprocess in accordance with the teachings of this invention for providinga uniform, smooth and continuous wall of bristles in the brush cavity ofa toothbrush having a curved lateral support wall.

DETAILED DESCRIPTION OF CERTAIN PREFERRED EMBODIMENTS OF THE PRESENTINVENTION

Referring now to the drawings, wherein like reference numerals representlike features in the several views, the preferred embodiments of atoothbrush in accordance with the teachings of the present invention areshown in FIGS. 3-6. FIGS. 3-6 relate to a toothbrush having a uniform,smooth, and continuous wall of bristles. However, designs other thanthose specifically set forth herein are also contemplated which wouldsimilarly provide a toothbrush having a uniform, smooth, and continuouswall of bristles and still be in accordance with the teachings of thepresent invention.

Referring now to FIG. 3, there is provided a manual toothbrush 1including an elongated handle 2 on one end and a head 10 on the otherend. The handle 2 may be conventional in shape and include features suchas ergonomic sizing, grasping features, bends, and coloration as desiredby the designer. The head 10 in FIG. 3 is shown in a octagonal shape,however, other shapes including round, oval, square, etc., may be usedwithout departing from the scope of this invention. Extending from thehead 10, substantially perpendicular to the longitudinal axis 3 of thetoothbrush 1 are a plurality of bristles 18 which as will be describedin more detail below formed as a uniform, smooth, and continuous wall.

FIG. 4 shows a top view of the head 10. The head 10 includes a cavity12. The cavity 12 has a plurality of lateral support members 14 formedtherein, and is defined by an edge 26 forming the outer perimeter of thecavity 12. The lateral support members 14 are preferably U-shaped, butother shapes may be utilized without departing from the scope of theinvention.

The head 10 also includes a brush face 16, which forms the top mostsurface of the head 10. Typically, the bristles 18 extend substantiallyperpendicular to the longitudinal axis 3 of the toothbrush 1 from thebottom 34 of the cavity 12 to a point above the brush face 16, as shownin FIG. 5.

In a preferred embodiment of FIG. 5, a staple 22 is used to affix thebristles 18. Preferably a plurality of individual bristles 18 arecombined to form a tuft 20. The tuft 20 is inserted into the cavity 12,arranged between a pair of legs 23 and 25 of adjacent lateral supportmembers 14 or between a leg and the edge 26 of the cavity 12, andaffixed to the toothbrush head 10 by the staple 22. The staple includesa top edge 30 and a bottom edge 28 thereof. It is preferable that thebristles are bent in half substantially at a center point of each of thebristles and arranged so that the bend portion is inserted into thelateral support member 14. Preferably still, the number of bristles 18grouped together to form a tuft 20 is sufficient to form a close fit inthe lateral support member 14. As such, the outer bristles 18 of a tuft20 will have a bend radius substantially similar to the radius of thelateral support member 14.

The bottom edge 28 of the retaining staple 22 forms the center of thebend radius of the bristles 18 as shown in FIG. 5. Given the outwardforces created by the presence of the staple 22, it is preferred to havethe height of the lateral support member 14 rise above the bottom edge28 of the staple 22. However, to assure the bristles between neighboringtufts 20 are in full contact prior to exiting the cavity 12, the legs23, 25 of the lateral support members 14 must stop short of the brushface 16. However, the edge 26 which may form a portion of the lateralsupport member may still rise to the level of the brush face 16. Thereis no convergence point on the edge 26 side of the lateral supportmember 14, thus the edge 26 preferably extends from the bottom 34 to thebrush face 16.

The final convergence point of the bristles 18 is controlled by thetop-most width of the lateral support member 14, and more specificallythe width of the legs 23 and 25, the distance between the top of thelateral support member 14 and the brush face 16, and the angle θ of thelegs 23 or 25 of the lateral support member 14 with respect to thebottom 34.

As shown in FIG. 5, the legs 23 or 25 of the lateral support member 14are relatively thick and maintain a substantially constant thickness. Inthis embodiment, the height of the lateral support member 14 isconsiderably less than the surface height of the brush face 16, and doesnot extend as close to the brush face 16, as in the embodiment shown inFIG. 6. As a result, the point of convergence 32 of the bristles 18 islower in the cavity 12 for the embodiment of FIG. 5.

FIG. 6 shows another embodiment wherein a plurality of lateral supportmembers 14 are formed along the bottom 34 of the cavity 12. The lateralsupport members 14 are formed of at least one leg 23 a and asubstantially concave base 24 a. The lateral support members may includea second leg 25 a, or alternatively, the edge 26 of the cavity 12. Asshown in FIG. 6, the legs 23 a and 25 a extend to a point approximatelythe same height as a top edge 30 of a staple 22.

As shown in FIG. 6, when the lateral support member is tapered such thatthe legs 23 a or 25 a is relatively thick at its base and becomesthinner and thinner as it proceeds towards the surface of the brush face16 a, the lateral support member 14 rises much closer to the surface ofthe brush face 16 a than the lateral support member of FIG. 5. Thisresults in the point of convergence 32 being higher from the cavity 12.In this embodiment, however, the point of convergence 32 remains belowthe surface of the brush face 16 a.

FIG. 7 depicts a further embodiment of the present invention, where thelateral support member 14 extends towards the brush face 16 to a pointbeyond the top surface 30 of the staple 22, but below the level of thebrush face 16. As with the example shown in FIG. 6, the convergencepoint is higher, in the cavity 12.

Another aspect of the present invention is shown in FIG. 8. The topsurface of the lateral support member may be formed in a non-flatorientation. This results in greater general stability for the bristles18 caused by the height of the legs 23. This non-flat orientation alsoincreases the uniformity and smoothness of the toothbrush as thebristles extend past the brush face 16 compared to straight lateralsupport members 14 having legs extending to substantially the sameheight as those of FIG. 8. This effect is caused by the dropping of theconvergence point 32 for the bristles between the legs 23 in thenon-flat section of the lateral support member 14.

While the foregoing examples have been discussed with respect to lateralsupport members having a substantially straight formation and disposedsubstantially longitudinally on the axis 3, other orientations areconsidered within the scope of the present invention. For example, FIG.9 depicts a portion of a toothbrush head 10 having a lateral supportmembers 14 formed in a curved orientation.

It should be understood that the objective reached above can also beachieved by a construction involving an increase in the thickness of thehead 10 perpendicular to the longitudinal axis 3 of the toothbrush 1.This results in an increase in the depth of the cavity 12, which in turnprovides for an increase in the height of the edge 26 around the cavity12. This increase in height effectively insures that the point ofconvergence of the bristles remains below the brush face, thuseliminating the gap A that is produced when using the methods shown inprior art of FIG. 1. In this embodiment, the edge 26 extends from thebottom 34 to a point minimally as high as the point of convergence 32 ofneighboring tufts 20. The lateral support members 14 may extend beyondthe top edge 30 of the staple 22, but not as far as the brush face 16.This results in a toothbrush having a uniform, smooth, and continuouswall of bristles 18 at the brush face 16.

However, while this method is contemplated, in the preferred embodimentthe thickness of the head 10 is not increased as this presents a moredesirable toothbrush, requiring less material and resulting in a morecompact toothbrush for easier use.

The preferred materials for construction of the toothbrush 1 of thepresent invention include a wide variety of moldable or injectableplastics such as thermoplastics. It is preferable that the toothbrushand head are molded as a single thermoplastic component. Alternatively,multiple plastic components could be formed and joined after formation.It is further preferable that the lateral support members 14 are formedduring the molding of the head 10 and are integral therewith.

Alternatively, the lateral support members 14 could be formed as part ofthe handle 2 and integrated with the head 10 when the components areassembled. Still further, the lateral support members 14 could be formedseparately and then added to the toothbrush as a component.

It is a further embodiment of the present invention that the head 10 isarranged on a powered toothbrush (not shown). The result is a poweredtoothbrush having a head 10 with a uniform, smooth and continuous wallof bristles affixed to one end and a handle disposed on the other end ofthe powered toothbrush. Typically, the handle comprises a powering meansfor actuating the head 10 of the powered toothbrush. The actuation maybe oscillating, rotary, reciprocating, or simple vibration, or acombination of motions. The head 10 may be removable from the powerproviding handle or formed of a single integrated unit as desired.

The desired objects of the present invention have been met by providinga toothbrush having a uniform, smooth, continuous wall of bristles whileusing lower cost traditional staple technology. This is accomplished bycontrolling the height of the legs 23 or 25 of the lateral supportmembers 14. Limiting the height of the legs to a point below the edge 26of the cavity effectively eliminates gaps between the tufts as theyextend past the brush face. Further, there is provided sufficientlateral support for the bristles to ensure that the bristles extendsubstantially perpendicular to the longitudinal axis of the toothbrush,and allow for easier insertion of subsequent bristle tufts when usingtraditional staple affixing methods.

Although the invention has been particularly shown and described withreference to certain preferred embodiments, it will be readilyappreciated by those of ordinary skill in the art that various changesand modifications may be made therein without departing from the spiritand scope of the invention.

1. A toothbrush comprising: an elongated member having a head at one endand a handle at the other end, generally aligned along a centrallongitudinal axis, said head having a brush face including a cavity fromwhich a plurality of bristles extend, said plurality of bristles beingarranged in a plurality of tufts so as to extend generally perpendicularto the central longitudinal axis; a plurality of lateral support membersextending upwardly from a base of the brush cavity; attachment meansprovided in said brush cavity for engaging at least one of the pluralityof tufts and for securing said one tuft between adjacent lateral supportmembers, said attachment means having a bottom edge and a top edge, andwherein each of the lateral support members extends to a predeterminedheight from the base of the brush cavity so as to reach at least theheight of the bottom edge of said attachment means in said brush cavity.2. The toothbrush of claim 1, wherein the lateral support member extendsto a predetermined height between the bottom edge of the attachmentmeans and the brush face.
 3. The toothbrush of claim 1, wherein at leastone of the plurality of tufts is affixed by the attachment means betweenone of the plurality of lateral support members and a side edge of thebrush cavity.
 4. The toothbrush of claim 1, wherein attachment means isa metal staple.
 5. The toothbrush of claim 1, wherein the lateralsupport members are substantially U-shape.
 6. The toothbrush of claim 1,wherein the lateral support members enable the bristles of the pluralityof tufts to contact one another at a point in the cavity below the brushface.
 7. The toothbrush of claim 1, wherein said attachment means formsa substantially uniform continuous layer of bristles extending from thebrush face.
 8. The toothbrush of claim 1, wherein the lateral supportmember has a non-flat top surface.
 9. The toothbrush of claim 1, whereinthe lateral support walls are curved.
 10. A powered toothbrushcomprising: an elongated member having a head at one end and a handle atthe other end, generally aligned along a central longitudinal axis, saidhead having a brush face including a cavity from which a plurality ofbristles extend, said plurality of bristles being arranged in aplurality of tufts so as to extend generally perpendicular to thecentral longitudinal axis; a plurality of lateral support membersextending upwardly from a base of the brush cavity; attachment meansprovided in said cavity at least for engaging one of the plurality oftufts and for securing said one tuft between adjacent lateral supportmembers, said attachment means having a bottom edge and a top edge, andwherein each of the lateral support members extends to a predeterminedheight from the base of the brush cavity so as to reach at least theheight of the bottom edge of said attachment means in said brush cavity.11. The toothbrush of claim 11, wherein the lateral support memberextends to a predetermined height between the bottom edge of theattachment means and the brush face.
 12. The toothbrush of claim 11,wherein at least one of the plurality of tufts is affixed by theattachment means between one of the plurality of lateral support membersand a side edge of the brush cavity.
 13. The toothbrush of claim 11,wherein attachment means is a metal staple.
 14. The toothbrush of claim11, wherein the lateral support members are substantially U-shape. 15.The toothbrush of claim 11, wherein the lateral support members enablethe bristles of the plurality of tufts to contact one another at a pointin the cavity below the brush face.
 16. The toothbrush of claim 11,wherein said attachment means forms a substantially uniform continuouslayer of bristles extending from the brush face.
 17. The toothbrush ofclaim 11, wherein the lateral support member has a non-flat top surface.18. The toothbrush of claim 11, wherein the lateral support walls arecurved.
 19. The toothbrush of claim 11, wherein the lateral supportmember extends to a predetermined height between the top edge of theattachment means and a top surface of said brush face.
 20. A lateralsupport member for holding bristles in a toothbrush comprising: asubstantially U-shaped formation formed in a cavity of the toothbrush,at least one leg of the U-shaped formation extending to a point betweena bottom edge of a staple and a brush face of the toothbrush securingthe bristles to the toothbrush.